Refrigerating apparatus



May 12, 1936. 'r. L. CHISHOLM REFRIGERATING APPARATUS Filed Sept. 29, 1930 2 sheets-Sheet 1 INVENTOR BY Wm, M.

Hi5 ATTORNEYS.

May 12, 1936. 'r. CHISHOLM 2,040,597

REFRIGERATING APPARATUS Filed Sept. 29, 1950 2 Sheets-Sheet 2 r43 hi7 i INVENTOR Ma. I: M

HIS ATTORNEYS Patented May 12, 1936 UNITED STATES PATENT OFFICE aarnrcaaa'rme mm'rus Application September 29, 1930, Serial No. 485,176

1 Claim.

This invention relates to refrigerating systems and particularly to the control of refrigerant passing through the evaporator thereof.

In refrigerating systems wherein a valve is provided for controlling the flow of refrigerant, such a valve, after considerable use, becomes worn due to the velocity of refrigerant flowing past the same during its open position, and will not properly engage its seat thus permit- 1 ting refrigerant to leak, when the valve is in closed position. When this condition occurs it is necessary to remove the valve and replace it with a new one or reface the surfaces thereof.

In the particular embodiment illustrated, such valve is employed for controlling the flow of refrigerant from the high pressure side of the refrigerating system to the low pressure side of such system. Heretofore when it was necessary to remove such a valve all refrigerant within a part of the system was required to be withdrawn therefrom and pumped or circulated to other parts of the system which, in the case of large reservoirs, required a considerable amount of time and rendered a service call costly. To this end it is one of the objects of my invention to provide improved means for preventing the escape of refrigerant from the system when the valve, which ordinarily controls such flow, is removed.

A further object of the invention is to provide a refrigerating system with a supplementing valve operated automatically to prevent the escape of refrigerant from the system when a part of the system is opened to remove the valve,

controlling the flow of refrigerant therein, to

be replaced or refaced.

A further object of the invention is to provide means including a valve for separating the low side from the high side of a refrigerating system which valve can be quickly removed without disassembling any portion of the system while automatically preventing the loss of refrigerant contained in the system so that the valve can be replaced in a minimum amount of time.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a fragmentary cross-sectional view in .a vertical plane of an evaporator constructed in accordance with the present invention connected to a refrigerating system shown diagram- 5 matically;

ically, the valve is shown responsive to a pre- Fig. 2 is an enlarged sectional view of a portion of the evaporator taken on the lines 2--2 of Fig. 1;

Fig. 3 is a sectional view of a portion of the evaporator showing certain parts thereof re- ,5 moved and showing the shut-off valve in closed position; and

Fig. 4 is a view of a portion of the evaporator taken on the lines H of Fig. 1.

Referring to the drawings iii designates a com- 10 pressor driven by an electric motor ii for withdrawing evaporated refrigerant from an evaporator l2. The refrigerant gas to be compressed enters compressor i0 through pipe i3 and is expelled through a pipe M. The compressed re- 15 frigerant passes through the condenser I! where it is cooled, in any suitable manner, and liquefles and from thence it passes into the receiver ii. The liquefied refrigerant then flows to evaporator i2 through pipe IT. The motor which 20 actuates the compressor in may be controlled in any suitable manner. For example'motor ii may be controlled by a switch l8 responsive to pressures in the low pressure side of the system.

The improved mechanism herein disclosed may 25 be used in various types of refrigerating systems. In the present embodiment, I have shown a valve as being responsive to a certain condi tion in the refrigerating system and more specifso determined level of liquid refrigerant within an evaporator.

Referring more particularly to Fig. 1 evaporator i2 comprises a header 20 and an end cover 2i attached to the header by bolts 22. The end cover 2i is provided with an inwardly extendi boss 23. Boss 23 is provided with a cylindrical opening 24 the inner end of which is provided with a relatively small opening 25 and a valve seat 40 25. A valve 21 cooperates with the valve seat 26 and has a stem 28' extending through the opening 25. The opening 24 is internally threaded to receive a screw plug 29 and is counterbored at 3i for the purpose of permitting a sealing wash- 45 er of suitable material such for example as a lead washer 32 to be clamped between the head of the plug 23 and boss 23 to prevent the escape of refrigerant from the evaporator at this point. A spring 33 is interposed between the back of valvev 50 21 and plug 29 and normally maintains the valve 21 upon its seat 26. The boss 23 is also provided with a horizontal passage 34 communicating with a vertical passage 35 which in turn communicates with the opening 24. Passage 34 is enlarged andscrewthreaded nearthefaceofend cover 2| to receive a coupling andshutoff valve 38 which is connected with pipe ll of the refrigerant liquefying unit. Details of the combined coupling and shut-off valve have been omitted from the drawings and this valve may be of any conventional structure suitable for'the purpose. Cover fl is also provided with a hole 81 which receives an inwardly extending pipe 38 and is connected'by coupling 3! to pipe It, the hole 31 providing an outlet for refrigerant gas evaporated in the evaporator I 2.

Float lever 4| is pivoted at 42, which pivot is supported by ears it formed on boss 28, and carries float ball 44. Float lever ll has a downwardly projecting arm which is adapted to engage with the stem 28 of valve 21 to move the valve away from its seat 20 whereby liquid refrigerant will pass through opening 2| into the header. After the level of the liquid refrigerant within header it rises to a certain height the arm 45 of lever II will move far enough to permit spring 33 to move valve 21 to closed position. In such a structure the valve is opened by the float but slightly whenmaintaining a certain predetermined level and liquid refrigerant flows past the valve into the header at a high velocity. The

velocity of this liquid refrigerant is so great that after the valve has been in use a short period of time it becomes worn and will not seat properly. This improper seating of the valve permits liquid refrigerant to leak into the header when the valve is closed thus causing ineflicient operation ot the refrigerant liquefying or circulating unit necessitating replacement of the valve.

My invention is therefore particularly directed to an improved system provided with automatically operated means for sealing refrigerant contained thereim when the valve is rendered inoperative and is removed. In carrying out the invention my improved system includes an evaporator structure provided with a circular plate 41 carried on lugs II which may be formed on the inner face of boss 23. Plate 41 has a circular tapered portion is providing a valve which is adapted to engage a circular seat II. The seat II is formed by a raised annular portion protruding from the inner face of boss 23 and located between the lugs 48. One end of a spring 52 abuts against the plate 41 and has its other end secured, by screws 53 to the bom I3. ent from the drawings, plate 41 and spring I! are slidably carried between the stem portion 2! of valve 21 and arm I! of float lever ii. The valve II is normally maintained in open position to permit the ingress of liquid refrigerant under control of valve 21. The spring I! is of less tension than spring 33 but of sufiicient tension to positively and automatically seat valve 49 upon its seat 5| when the tension of spring 33 is less ened or when spring 33 is removed.

The height of the liquid level within header 20 is controlled by the tension of spring 33 which must also overcome the tension of spring 52. The spring 33 can be exchanged for one of greater or less tension when desired for controlling the force required to open or close the valve 21.

In the present embodiment the improved structure provides a valve separating the high and low sides of a refrigerating system which valve is readily removable from the exterior of the header without dismantling the evaporator. The valve 21 may be readily removed from the header when Asapparnotoperaflmcorrectiywithout withdrawingrefrigerantcontainedintheevaporatorand mmpingthisrefrigeranttootherpartsorelementsof thesystem. Inordertoremovethevalvell fromtheheaderllwhennotflmctioningproperly 5 themanual shut-oilvalve,containedinthecouplingtlconnectingtheliquidrefrigerantslmpiy pipe II to thesevaporator. is of valve it preventsrefrigei'ant from-flowing into theopeningflandtheplugllmaythenberemovedfromtheendcoverll. II releasesthetensionofspring and permits spring I! toforcevalvellonplatell,

.intoengagementwithitsseat n. Itistobeunderstoodthattheconstructionandan'angement oftheparts-permitsvalvetocloseautomaiicallywhenvalvellismoveilfromitscontrolling position'or when spring a is rendered imperative for closing valve 21. This preferably occurs assoonasthepluglqisloosenedslightlyand prior to the time the'plug is entirely removed from the opening 24. Thus refrigerant containedintheevaporator andtheremainderofthe system is prevented from escaping therefrom. Theopeninglland y tlandflaremade small, therefore the amount of refrigerant contained in these and which refrigerant escapes when the plug 2! and valve 21 are removed, is negligible and will not cause injurious effectstotheserviceman'. I

From the forego ng it is apparent thatI have provided an improved system employing a valve therein for separating the high and low pressure sides of the systun which valve canbequicklyandreadilyremovedwithoutthe as necessity of withdrawing refrigerant from the evaporator which evaporator is also provided with automatically operated means for preventing the loss of refrigerant from the system.

While the form of t of theinvention 40 as herein disclosed, constitutes a preferred form, it is to be lmderstood that otherforms might be adopted,all comingwithin thescopeoftheclaim which follows.

What is claimed isas follows:

An evaporator of a refrigerating system comprising in combination. walls defining a closed chamber providing a reservoir for liquid refrigerant, one wall of said chamber having a formed therein for the ingress of liquid refrigerant to the reservoir, a valve within the confines of said chamber walls and positioned in the passage in said one chamber wall, means 1011101111811! maintainingsaid valve closed, afloat withinsaid chamber responsive to the level of liquid refrigerant therein for actuating said valve from its normal closed position to permit fiow of. refrigerant or reservoir.

THEODORE L. CHIBEOLIL 

